French cinema and television standards are like California pollution standards; more strict than the norm, with active regulation and monitoring to keep standards high for this important section of their industrial and consumer base.
The SMPTE and ISO rules for screen brightness are clear. Luminance Uniformity at the corners and sides of the screen is specified at 85% of the luminance at the center of the screen. There is an allowed tolerance in theaters – 70% to 90% of the center level. (The center level is 48 candelas per square meter, with a tolerance of 10.2 cd.m2.)
The French standard is tighter, specifying no greater than 75% at the corners and edges. The CNC is about to release a technology statement that will abdicate their role as the arbiters of quality in this regard.
The CNC is the group who sets the the "AFNOR" standards for French cinema (and TV). This is the group who wrote in 2007 that once the SMPTE specifications for digital cinema technology are finalized that they "would have the force of law" in France and on the international level. (See: Force of Law; France Issues DCinema Document)
And yet, this very group is about to allow 'silver screens' to be within the actual standard with the reasoning; that commercially, silver screens have become a de facto standard. This is the equivalent of allowing the old 625-line/50 field per second interlaced video as an acceptable HD TV standard because there are so many TVs of that nature in the field. The reality is that silver screens – actually, aluminum painted screens – for passive 3D systems (the 'cheaper' RealD and MasterImage systems) cannot provide the mandated levels of light except to perhaps 10 seats in the theater. The fall-off in quality from using silver screens is the number one worst aspect of 3D presentations. And when a 2D movie is played on them, the results are a disaster: dark and gray patches, diminishing light to every seat except the one "measured" position, screens that cannot be cleaned, and which get darker in fewer years than the normal screen.
You can see the reply by several French cinema organizations at the following link: Respecter la lumière dans les salles obscures
Roughly translated that is: Respect the light in the darkened theater.
The players are no slouches. They are the technical organizations of every stage of the movie making process. It seems that they are respectful, but they are forceful. What they didn't say was that was that the CNC should be embarrassed. What they didn't say was that the artist and technology groups will create a grass roots education plan if they continue with the abdication of standards in the theater for financial reasons.
We are looking for a better english translation, but until we have one, this will have to suffice:
Respect the Light in Darkened Theater 22 June 2011
The CNC is about to sign a decision to amend the technical specifications – Requirements for Registration – of cinema theaters. The proposed text refers to the French standard for digital cinema, but with the "amputation" of the article about the difference in luminance (point 5.1.2 of the standard 27100).
That article provides that the difference in luminance between the brightest spot and the lowest point of a bright image on a screen can not exceed 25%. This aspect of the standard is essential. It guarantees the respect of light and contrast of the image desired by the director and the cinematographer and allows that all the spectators in the same room see the same film.
The exception to this standard is clearly intended to allow the spread of "silver screens" designed primarily for 3D projections. At this time, three large French circuits equip themselves large amounts of these screens ...
In the event that a classic 2D projection is performed on a silver screen, over 80% of the audience of a room would not see the film in the technical and with the 'artistic intention' that the directors, producers and technicians have designed.
This proposal is a dramatic decline in the quality and respect of the works: we sacrifice the quality of films, and the moral rights of authors, on behalf of the immediate profit potential of 3D, and seriously risk the experience in the auditorium.
We request of the CNC:
• to reverse its decision and enforce the entirety of the standard French NF S27100 particularly on point spreads luminance, taken by the international standard ISO digital cinema,
• to define together the means to monitor the implementation of this standard after a systematic inspection of the CST.
Signed
ACID Fabienne Hanclot 01 44 89 99 71 /
AFC Carolina Champetier 01 42 64 41 41 /
ARP Florence Gastaud 01 53 42 40 00 /
CST Laurent Hebert 01 53 04 44 00 /
the FICAM Hervé Chateauneuf 01 45 05 72 47 /
SACD Agnes Mazet 01 40 23 45 11 /
SRF's Cyril Seassau 01 44 89 99 65
For our earlier articles on the flaws of using silver screens see:
Scotopic Issues with 3D, and Silver Screens
23 degrees...half the light. 3D What?
Subscribe to RSS Feed